Boresight device and method

ABSTRACT

A modular system facilitates alignment of a simulation laser with the sights of a weapon. The modular assembly can be attached to the barrel of a weapon. A user can first align a target relative to the sights of the weapon. The laser can then be aligned with the target.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/602,497 filed Aug. 18, 2004 and entitled “Boresight Device and Method”.

FIELD OF THE INVENTION

The invention pertains to combat training and simulation systems. More particularly, the invention pertains to devices usable to align small arms transmitters in connection with combat training and simulation.

BACKGROUND

Current forms of combat training and simulation often include the use of a laser-based combat simulation system, the Multiple Integrated Laser Engagement System (MILES). Such systems usually associate laser-based transmitters with weapons being used to carry out the training or simulation exercise. Such transmitters can be coupled to a variety of small arms including rifles of various types, machine guns as well as vehicle-based cannons and the like. Laser beams from such transmitters are usually invisible to the naked eye.

To produce maximum value from the training or simulation exercise, small arms transmitters (SATs) need to be aligned to the sights of the associated weapon. This is regardless of whether those sights are aligned to the weapon or not. With this configuration, as the soldier trains using his/her sights, as he/she would in combat, the SAT will be correctly aligned, preferably with appropriate drop and drift compensation, with the physical sights on the weapon.

One known way of achieving the boresight alignment of the SAT to the weapon's sights is to sight the weapon on a target some 25 meters down range, and adjust the SAT laser beam until it coincides with that target (or with a pre-determined offset). While an excellent approach in principle, it is very cumbersome and time consuming to execute, and requires special equipment to render the invisible laser beam visible.

Alternately, an alignment fixture can be used. Known alignment fixtures are both cumbersome and expensive. Additionally, they are vendor specific and can only be used with the respective vendor's SATs. Also, many of the known fixtures are weapon specific. As a result, the user needs to purchase an individual alignment fixture for each vendor's SAT and for each weapon type. This increases user's initial procurement, total logistics and maintenance costs.

An alignment solution that provides a user with a universal system that enables the user to align most of the SATs available on the market to most of the existing small arms would be desirable. It would be preferable if common alignment equipment could be used with a variety of different weapons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall view of a system in accordance with the invention;

FIG. 1A is a more detailed view of components of the system of FIG. 1;

FIG. 2 is an enlarged partial view of a target assembly useable in the system of FIG. 1A;

FIG. 3 illustrates steps of a method in accordance with the invention; and

FIG. 4 is a block diagram of an embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiment illustrated.

In one embodiment of the invention, an optical lens can be used to bring a target in from any distance to the focal plane of a lens, much as the sun's image is brought to the focal plane of a burning-glass lens. Therefore, if a lens is placed in front of the weapon so that the soldier, in using the normal sights of the weapon looks through the lens, what he/she sees is whatever is at the focal plane of the lens.

A small visible alignment element such as a glowing red or green dot or cross in the focal plane will enable the soldier to align that dot or cross to the sights of the weapon if the element can be moved to align with the sights. This can be accomplished by locating the element on the focal plane on an X/Y movable stage. This stage can be motorized with a joystick or multi-position switch control that the soldier could operate while peering through the sights of the weapon for ease and speed of accomplishing this task. When the alignment element is aligned with the sights of the weapon it is boresighted to the weapon.

The next step is to align the SAT laser beam to the same location. If the alignment element is located on the focal plane of a CCD or CMOS camera, the SAT beam can be sent through another portion of the same lens described above and maneuvered so that it is centered on the alignment element. LCD readout can be used to display the angular location of the SAT beam, rendering it visible. In this way the SAT beam, using the normal adjustments, using first and second prisms therein, known as Risleys, can be oriented to be parallel to the weapon's line of sight because, by definition, parallel light paths entering a lens will coincide at the same lateral point in the lens focal plane. The SAT is therefore boresighted to the sights of the weapon. Offsets for drop and drift can be incorporated.

The lens, CCD, and other equipment, can be mounted in a common housing and releasably attached to the barrel of a weapon being sighted. The releasable attachment can be effected by using a weapon bore rod or a clamp which attaches to the outside of the gun barrel. It is very quick and convenient to mount and demount with these configurations. It is only necessary that the mount be stable during the boresighting procedure. Any possible mount/demount variations in precise mechanical location of the boresight device are not important because this boresight procedure does not depend on mechanical alignment with respect to the weapon bore, only to the weapon's sights.

For weapons having a large lateral offset between the weapon's line of sight and the SAT line of radiation, a lens must be used that is sufficiently large to simultaneously capture both the soldier's line of sight and the path of the SAT radiation. However, only a rectangular section of the several-inch diameter lens is used—enough to contain the weapon line of sight at one end of the section, and the SAT radiation at the other end of the section. The rest of the lens can be cut away.

A red dot, if used, will preferably be about a milliradian in diameter, or less. For a 10-centimeter focal length lens this means that the dot should be no larger than 100 microns in diameter. One way of creating a red dot would be to have it be the end of a 100-micron core-diameter optical fiber, illuminated at the other end by a red LED or laser diode. This fiber end could be located in, or closely in front of, the CCD focal plane. An alternative would be to insert a 100-micron ball or some other shiny object at the desired location and side-illuminating it with a red laser.

In another aspect of the invention, the CCD can be eliminated. The SAT beam can be made visible by incorporating in the SAT a co-linear visible red laser beam, which had previously been made coincident with the SAT beam. In this way the soldier can see both the red aligning dot (or cross) and the red dot from the SAT.

The procedure would be to first align the red dot (or a cross) to the weapon sights as described above, and then activate the SAT's built-in red laser and adjust the Risleys until its red dot is centered in the weapon sights. The weapon is therefore boresighted to the weapon. Drop/drift corrections can be incorporated by having an illuminated scale at the lens focal plane to enable any desired offset.

As described above, one way of boresighting the SAT laser to the iron sights is to provide a visible laser beam coincident with the SAT invisible beam. The visible beam would be turned on only during initial boresight adjustments. It would be visible down range at some target of opportunity easily visible by the iron sights. By adjusting the SAT laser transmitter until the visible beam is centered on the target, which in turn is centered in the iron sights, the SAT invisible laser beam is automatically also boresighted to the iron sights.

In order to be able to use the same SAT optics, including the Risley assembly, for both lasers, both laser sources must be optically at exactly the same physical location with respect to the optic's focal point. In one embodiment a SAT laser can be used which emits two different wavelengths from the same point. Alternately, optical means can be employed to introduce the second beam. This can be done by using a beam splitter to fold the second beam into exact coincidence with the SAT beam.

In accordance with this aspect of the invention, a second, visible diode laser can be located close to the SAT diode laser, and parallel to it. The beam from the second laser is bent 90 degrees toward a beamsplitter in the SAT laser beam. The beamsplitter bends the visible beam 90 degrees to make it coincident with the SAT beam. The visible laser is adjusted, similarly to the way we adjust the SAT lasers, to focus it.

Preferably, the visible laser would emit at the peak of the human visual response in the green region of the spectrum. An alternate current choice for the visible beam wavelength is a very common red laser diode emitting at 655 nm.

FIGS. 1, 1A illustrate an alignment device 10 in accordance with the invention. The device 10 provides an optional clamp C to which a gun or weapon W can be fixedly attached for alignment purposes.

The weapon W is of a type which has spaced-apart sights 14 a, b and a barrel B. Sight 14 a, is proximal to an eye of the user, and 14 b displaced from the eye of the user. The sight 14 a could, for example, be formed as a circular or annular opening. The sight 14 b could be formed as a post. The user aligns the post 14 b with the center of member 14 a when sighting the weapon W.

A SAT 20 includes a base that is attached to barrel B of the weapon W. The SAT can be clamped to the weapon using a conventional quick release clamp.

A boresight device 30 includes a housing 30-1. Brackets 30-2 attach housing 30-1, via mounting rod or tube 30-3 to quick release clamps or brackets 304. Brackets 304 releasably attach device 30 to barrel B of weapon into carry out a boresighting operation.

It will be understood that the exact details of the SAT and laser 20 are not limitations of the present invention. The SAT and laser 20 could emit either a visible or an invisible beam 22 of radiant energy. The beam 22 is emitted such that it is generally parallel to the line of sight of the user looking through gunsights 14 a, b.

Device 30 includes a collecting lens 26 located between the muzzle of the weapon W and a folding mirror 30 a. A second folding mirror 30 b can be provided to direct the light beams bent by the mirror 30 a back toward a moveable target assembly indicated generally at 32.

It will be understood that the mirrors 30 a, b do not represent limitations of the invention. They could be omitted without departing from the spirit and scope of the invention.

FIG. 2 illustrates additional details of the target assembly 32. It will be understood that target assembly 32 also carries a video camera, such as a CCD camera 34 with a lens 34 a and a beam splitter 36.

The target assembly can be moved in x, y perpendicular directions, in a plane perpendicular to the incident laser beam, by independently controlled motors 40, 42. Control of the motors 40, 42 can be effected from a control unit 44 by using a form of a control member such as a joystick 46. Alternately, separate switches or keys, a mouse, trackball or the like all without limitation could be used.

In operation, the weapon W is clamped into assembly 10 using optional clamp C. Device 30 can be clamped to or coupled to the barrel B of the weapon W as described above.

A user, or soldier, can use the joystick 46 to move the cross-shaped target cut-out indicated generally at 50 (carried for example by 32-1) into alignment with the sights 14 a, b of the weapon W. In this circumstance, the line of sight of the user, through the sights 14 a, b is now aligned relative to the target cut-out.

The laser 20 can then be energized, which in turn causes it to emit beam 22 which passes through collecting lens 26, off the mirrors 30 a, b and through beam splitter 36. The spot from the beam 22, after passing through beam splitter 36, lens 34 a and impinges upon CCD camera 34. The spot is then transmitted to a display 54 and appears on the same image as does the cross-shaped target cut-out which had previously been aligned with the sights 14 a, b.

The orientation of the laser 20 is now adjusted using first and second prisms therein, known as Risleys. Adjustment of laser beams using Risleys is known to those of skill in the art and need not be described further.

The spot present on the display 54, from beam 22, can then be aligned relative to the sights 14 a, b so as to be located on the cross-hairs of the cross-shaped target. The alignment process is thus concluded.

The weapon W can be removed from the system 10. The next weapon can be inserted and clamped to the alignment fixture using clamp C and the process repeated.

FIG. 3 illustrates a method 100 of carrying out the above process. In steps 102-106, the user or soldier aligns the sights 14 a, b of the weapon W as illustrated therein. The motor driven stage 32 with the CCD camera 34 can be moved in the x and y directions 40 a, 42 a, so as to align the cross-shaped target 50 in the center of the sights 14 a, b, as illustrated in step 106. The laser 20 is then turned on, step 108. Alignment of the laser beam 22 using the Risleys in the laser 20 results in locating of the spot 22 a of the beam 22 on the cross-hairs 50 as illustrated in step 5.

It will be understood that the target structure 32 could in fact be the CCD camera 34. This configuration would eliminate the beam splitter 36. The screen of the CCD could be provided with a small side-illuminated sphere of glass or sapphire or a cross of a thin scattering fiber optic which could be end illuminated. Either the sphere or the glass or plastic fiber could be directly formed to the surface of the CCD.

In one embodiment of the invention, a portable battery operated universal alignment fixture includes a Controller Module (CM) such as module 44, Target Module (TM) such as module 30, and interconnecting cable (see FIG. 4). The CM contains the video processing circuit, LCD for viewing the target cross-hair and the overlaid image of the SAT laser beam, the rechargeable battery, power management circuit and the control switches.

The TM contains a large lens for viewing the crosshair through the sights of the weapon, the opto-electronics required for the alignment, and a Universal Weapon Interface (UWI), such as clamps 30-4, for coupling to the weapon. Alternately, the UWI can slide into, or, mount in the bore of the barrel B of the weapon W. Both modules are interconnected by a power/control cable.

The battery is sufficient for up to 10 hours of typical operation. The battery can be recharged using included power adapter that requires either 110V or 220V AC power depending on the customer's need.

The Target Module is mechanically coupled with the weapon through the Universal Weapon Interface. Any possible mount/demount variations in precise mechanical location of the UWI are not important because the boresight procedure does not depend on mechanical alignment with respect to the weapon bore, only to the weapon sights.

In summary, an optical lens, such as lens 26, is used to bring the target in from any distance to the lens focal plane. The lens is placed in front of the weapon W so that the soldier, in using the normal weapon sights 14 a, b, looks through the lens 26, and observes a small green cross-hair target such as target 50. The Controller Module's joystick 46 enables the soldier to align this cross-hair to the weapon's sights.

A Coarse/Fine switch allows the soldier to switch between fast (coarse) and slow (fine) movement of the cross-hair. Once the Crosshair is aligned with the weapon sights, the system 10 is ready for the SAT adjustment.

The next step is to align the SAT laser beam to the crosshair 50 viewed on the LCD 54 of the Controller Module. To accomplish this, the soldier simply switches the Motor/Camera switch to Camera position and enables SAT boresight mode. The SAT beam 22 is sent through another portion of the same lens that was used to view through the weapon sights and the SAT's Risleys are maneuvered so as to center the beam 22 on the crosshair 50 displayed on the LCD 54. Once the beam is at the center of the crosshair, the SAT has been boresighted to the weapon sights.

From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims. 

1. A modular apparatus comprising: a clamp for releasable attachment to a weapon; a housing carried by the clamp; a platform movable in two directions carried by the housing; a visual indicium carried by the platform; and manually operable control circuits for moving the indicium to a selected location.
 2. An apparatus as in claim 1 which includes a lens having a predetermined focal length with the indicium displaced from the lens by the focal length.
 3. An apparatus as in claim 1 which includes a lens having a predetermined focal length and a first mirror.
 4. An apparatus as in claim 3 which includes at least a second mirror, the lens, and the two mirrors form an optical path between a first surface of the housing and the visual indicium.
 5. An apparatus as in claim 4 where a distance parameter between the first housing surface and the visual indicium is less than the focal length of the lens.
 6. An apparatus as in claim 1 which includes at least one lens, the lens having a predetermined focal length and an optical beam folder.
 7. An apparatus as in claim 6 where the housing has a first surface and where a distance parameter between the first housing surface and the visual indicium is less than the focal length of the lens.
 8. An apparatus as in claim 2 where the visual indicium receives incident monochromatic light.
 9. An apparatus as in claim 8 where the incident monochromatic light has a wavelength that falls in a human visible range of wavelengths.
 10. An apparatus as in claim 2 which includes a sensor of monochromatic light incident, at least in part on the visual indicium.
 11. An apparatus as in claim 10 where the sensor responds to incident monochromatic light having a wavelength that falls outside of a human visible range of wavelengths.
 12. An apparatus as in claim 11 where at least one output from the sensor is coupled to a device that displays incident monochromatic light with a wavelength that falls in a human visible range of wavelengths.
 13. An apparatus as in claim 2 which includes first and second switches for coupling electrical energy to the platform for movement in each of the two directions.
 14. An apparatus as in claim 2 which includes a beam splitter and a two dimensional radiant energy sensor.
 15. An apparatus as in claim 14 which includes a human perceptible display for viewing a representation of outputs from the radiant energy sensor.
 16. A method comprising: moving a visual indicium into a predetermined location in a human perceptible fluid of view; establishing a beam of monochromatic light; directing the beam toward the field of view so as to be incident thereon at a first location; and moving the beam so that the first location corresponds to the predetermined location.
 17. A method as in claim 16 which includes fixing the beam so that first location continues to correspond to the predetermined location.
 18. A method as in claim 16 which includes sighting along first and second references to establish a line of sight to the predetermined location.
 19. A method as in claim 18 where directing includes directing the beam substantially in parallel with the line of sight.
 20. A method as in claim 16 which includes a line of sight along first and second establishing spaced apart sights of a weapon to the predetermined location.
 21. A method as in claim 20 which includes coupling a source for the beam of mono-chromatic light to the weapon.
 22. A method as in claim 21 which includes coupling a modular lens-mirror assembly to the weapon where the line of sight to the predetermined location extends, in part through the assembly.
 23. A method as in claim 22 which includes folding the line of sight in the assembly.
 24. A method as in claim 23 which includes carrying a sensor of the mono-chromatic light on the assembly.
 25. A method as in claim 24 which includes presenting incident sensed mono-chromatic light in a human perceptible form.
 26. A method as in claim 25 where moving includes moving the human perceptible form.
 27. A method as in claim 26 where moving the human perceptible form includes altering a direction of transmission of the beam.
 28. A modular boresighting apparatus comprising: a housing; a clamp attachable to a weapon, the clamp carried by the housing; a lens having a predetermined focal length carried by the housing; at least one beam reflector carried by the housing; a member movable first and second perpendicular directions, the member carried by the housing.
 29. An apparatus as in claim 28 which includes a two-dimensional sensor of incident radiant energy, the sensor carried by the housing.
 30. An apparatus as in claim 29 which includes control circuits coupled to the member.
 31. An apparatus as in claim 30 where the control circuits include a manually manipulatable control device for positioning the member.
 32. An apparatus as in claim 31 where the control device is selected from a class which includes at least a switch, a joy stick, a mouse, and a track ball.
 33. An apparatus as in claim 31 where the control circuits include a display, the display visually presents radiant energy incident on the sensor.
 34. A method comprising: moving a visual indicium into a predetermined location in a human perceptible field of view; transmitting at least a beam of human perceptible monochromatic light toward the predetermined location; adjusting the beam of human perceptible light so that it is incident on the predetermined location.
 35. A method as in claim 34 which includes terminating transmission of the human perceptible beam of light, and, transmitting, at least intermittently a monochromatic beam of light that is not visible to human eyes. 